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Struct function
このページを編集する際は，編集に関する方針に従ってください． 概要 *gcc-4.1.0/gcc/function.hにて定義 * 実装 159 /* This structure can save all the important global and static variables 160 describing the status of the current function. */ 161 162 struct function GTY(()) 163 { 164 struct eh_status *eh; 165 struct eh_status *saved_eh; 166 struct expr_status *expr; 167 struct emit_status *emit; 168 struct varasm_status *varasm; 169 170 /* The control flow graph for this function. */ 171 struct control_flow_graph *cfg; 172 struct control_flow_graph *saved_cfg; 173 bool after_inlining; 174 175 /* For tree-optimize.c. */ 176 177 /* Saved tree and arguments during tree optimization. Used later for 178 inlining */ 179 tree saved_args; 180 tree saved_static_chain_decl; 181 tree saved_blocks; 182 tree saved_unexpanded_var_list; 183 184 /* For function.c. */ 185 186 /* Points to the FUNCTION_DECL of this function. */ 187 tree decl; 188 189 /* Function containing this function, if any. */ 190 struct function *outer; 191 192 /* Number of bytes of args popped by function being compiled on its return. 193 Zero if no bytes are to be popped. 194 May affect compilation of return insn or of function epilogue. */ 195 int pops_args; 196 197 /* If function's args have a fixed size, this is that size, in bytes. 198 Otherwise, it is -1. 199 May affect compilation of return insn or of function epilogue. */ 200 int args_size; 201 202 /* # bytes the prologue should push and pretend that the caller pushed them. 203 The prologue must do this, but only if parms can be passed in 204 registers. */ 205 int pretend_args_size; 206 207 /* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is 208 defined, the needed space is pushed by the prologue. */ 209 int outgoing_args_size; 210 211 /* This is the offset from the arg pointer to the place where the first 212 anonymous arg can be found, if there is one. */ 213 rtx arg_offset_rtx; 214 215 /* Quantities of various kinds of registers 216 used for the current function's args. */ 217 CUMULATIVE_ARGS args_info; 218 219 /* If nonzero, an RTL expression for the location at which the current 220 function returns its result. If the current function returns its 221 result in a register, current_function_return_rtx will always be 222 the hard register containing the result. */ 223 rtx return_rtx; 224 225 /* The arg pointer hard register, or the pseudo into which it was copied. */ 226 rtx internal_arg_pointer; 227 228 /* Opaque pointer used by get_hard_reg_initial_val and 229 has_hard_reg_initial_val (see integrate.hc). */ 230 struct initial_value_struct *hard_reg_initial_vals; 231 232 /* List (chain of EXPR_LIST) of labels heading the current handlers for 233 nonlocal gotos. */ 234 rtx x_nonlocal_goto_handler_labels; 235 236 /* Label that will go on function epilogue. 237 Jumping to this label serves as a "return" instruction 238 on machines which require execution of the epilogue on all returns. */ 239 rtx x_return_label; 240 241 /* Label that will go on the end of function epilogue. 242 Jumping to this label serves as a "naked return" instruction 243 on machines which require execution of the epilogue on all returns. */ 244 rtx x_naked_return_label; 245 246 /* List (chain of EXPR_LISTs) of all stack slots in this function. 247 Made for the sake of unshare_all_rtl. */ 248 rtx x_stack_slot_list; 249 250 /* Place after which to insert the tail_recursion_label if we need one. */ 251 rtx x_tail_recursion_reentry; 252 253 /* Location at which to save the argument pointer if it will need to be 254 referenced. There are two cases where this is done: if nonlocal gotos 255 exist, or if vars stored at an offset from the argument pointer will be 256 needed by inner routines. */ 257 rtx x_arg_pointer_save_area; 258 259 /* Offset to end of allocated area of stack frame. 260 If stack grows down, this is the address of the last stack slot allocated. 261 If stack grows up, this is the address for the next slot. */ 262 HOST_WIDE_INT x_frame_offset; 263 264 /* A PARM_DECL that should contain the static chain for this function. 265 It will be initialized at the beginning of the function. */ 266 tree static_chain_decl; 267 268 /* An expression that contains the non-local goto save area. The first 269 word is the saved frame pointer and the second is the saved stack 270 pointer. */ 271 tree nonlocal_goto_save_area; 272 273 /* Insn after which register parms and SAVE_EXPRs are born, if nonopt. */ 274 rtx x_parm_birth_insn; 275 276 /* List of all used temporaries allocated, by level. */ 277 struct varray_head_tag * GTY((param_is (struct temp_slot))) x_used_temp_slots; 278 279 /* List of available temp slots. */ 280 struct temp_slot *x_avail_temp_slots; 281 282 /* Current nesting level for temporaries. */ 283 int x_temp_slot_level; 284 285 /* This slot is initialized as 0 and is added to 286 during the nested function. */ 287 struct var_refs_queue *fixup_var_refs_queue; 288 289 /* For integrate.c. */ 290 int inlinable; 291 int no_debugging_symbols; 292 rtvec original_arg_vector; 293 tree original_decl_initial; 294 295 /* Highest label number in current function. */ 296 int inl_max_label_num; 297 298 /* Function sequence number for profiling, debugging, etc. */ 299 int funcdef_no; 300 301 /* For flow.c. */ 302 303 /* Highest loop depth seen so far in loop analysis. Used in flow.c 304 for the "failure strategy" when doing liveness analysis starting 305 with non-empty initial sets. */ 306 int max_loop_depth; 307 308 /* For md files. */ 309 310 /* tm.h can use this to store whatever it likes. */ 311 struct machine_function * GTY ((maybe_undef)) machine; 312 /* The largest alignment of slot allocated on the stack. */ 313 unsigned int stack_alignment_needed; 314 /* Preferred alignment of the end of stack frame. */ 315 unsigned int preferred_stack_boundary; 316 /* Set when the call to function itself has been emit. */ 317 bool recursive_call_emit; 318 /* Set when the tail call has been produced. */ 319 bool tail_call_emit; 320 321 /* Language-specific code can use this to store whatever it likes. */ 322 struct language_function * language; 323 324 /* For reorg. */ 325 326 /* If some insns can be deferred to the delay slots of the epilogue, the 327 delay list for them is recorded here. */ 328 rtx epilogue_delay_list; 329 330 /* How commonly executed the function is. Initialized during branch 331 probabilities pass. */ 332 enum function_frequency { 333 /* This function most likely won't be executed at all. 334 (set only when profile feedback is available). */ 335 FUNCTION_FREQUENCY_UNLIKELY_EXECUTED, 336 /* The default value. */ 337 FUNCTION_FREQUENCY_NORMAL, 338 /* Optimize this function hard 339 (set only when profile feedback is available). */ 340 FUNCTION_FREQUENCY_HOT 341 } function_frequency; 342 343 /* Maximal number of entities in the single jumptable. Used to estimate 344 final flowgraph size. */ 345 int max_jumptable_ents; 346 347 /* UIDs for LABEL_DECLs. */ 348 int last_label_uid; 349 350 /* Line number of the end of the function. */ 351 location_t function_end_locus; 352 353 /* Array mapping insn uids to blocks. */ 354 struct varray_head_tag *ib_boundaries_block; 355 356 /* The variables unexpanded so far. */ 357 tree unexpanded_var_list; 358 359 /* Assembly labels for the hot and cold text sections, to 360 be used by debugger functions for determining the size of text 361 sections. */ 362 363 const char *hot_section_label; 364 const char *cold_section_label; 365 const char *hot_section_end_label; 366 const char *cold_section_end_label; 367 368 /* String to be used for name of cold text sections, via 369 targetm.asm_out.named_section. */ 370 371 const char *unlikely_text_section_name; 372 373 /* A variable living at the top of the frame that holds a known value. 374 Used for detecting stack clobbers. */ 375 tree stack_protect_guard; 376 377 /* Collected bit flags. */ 378 379 /* Nonzero if function being compiled needs to be given an address 380 where the value should be stored. */ 381 unsigned int returns_struct : 1; 382 383 /* Nonzero if function being compiled needs to 384 return the address of where it has put a structure value. */ 385 unsigned int returns_pcc_struct : 1; 386 387 /* Nonzero if the current function returns a pointer type. */ 388 unsigned int returns_pointer : 1; 389 390 /* Nonzero if function being compiled can call setjmp. */ 391 unsigned int calls_setjmp : 1; 392 393 /* Nonzero if function being compiled can call alloca, 394 either as a subroutine or builtin. */ 395 unsigned int calls_alloca : 1; 396 397 /* Nonzero if function being compiled called builtin_return_addr or 398 builtin_frame_address with non-zero count. */ 399 unsigned int accesses_prior_frames : 1; 400 401 /* Nonzero if the function calls __builtin_eh_return. */ 402 unsigned int calls_eh_return : 1; 403 404 /* Nonzero if function being compiled receives nonlocal gotos 405 from nested functions. */ 406 unsigned int has_nonlocal_label : 1; 407 408 /* Nonzero if function being compiled has nonlocal gotos to parent 409 function. */ 410 unsigned int has_nonlocal_goto : 1; 411 412 /* Nonzero if the current function is a thunk, i.e., a lightweight 413 function implemented by the output_mi_thunk hook) that just 414 adjusts one of its arguments and forwards to another 415 function. */ 416 unsigned int is_thunk : 1; 417 418 /* This bit is used by the exception handling logic. It is set if all 419 calls (if any) are sibling calls. Such functions do not have to 420 have EH tables generated, as they cannot throw. A call to such a 421 function, however, should be treated as throwing if any of its callees 422 can throw. */ 423 unsigned int all_throwers_are_sibcalls : 1; 424 425 /* Nonzero if profiling code should be generated. */ 426 unsigned int profile : 1; 427 428 /* Nonzero if stack limit checking should be enabled in the current 429 function. */ 430 unsigned int limit_stack : 1; 431 432 /* Nonzero if current function uses stdarg.h or equivalent. */ 433 unsigned int stdarg : 1; 434 435 /* Nonzero if the back-end should not keep track of expressions that 436 determine the size of variable-sized objects. Normally, such 437 expressions are saved away, and then expanded when the next 438 function is started. For example, if a parameter has a 439 variable-sized type, then the size of the parameter is computed 440 when the function body is entered. However, some front-ends do 441 not desire this behavior. */ 442 unsigned int x_dont_save_pending_sizes_p : 1; 443 444 /* Nonzero if the current function uses the constant pool. */ 445 unsigned int uses_const_pool : 1; 446 447 /* Nonzero if the current function uses pic_offset_table_rtx. */ 448 unsigned int uses_pic_offset_table : 1; 449 450 /* Nonzero if the current function needs an lsda for exception handling. */ 451 unsigned int uses_eh_lsda : 1; 452 453 /* Nonzero if code to initialize arg_pointer_save_area has been emitted. */ 454 unsigned int arg_pointer_save_area_init : 1; 455 456 /* Number of units of general registers that need saving in stdarg 457 function. What unit is depends on the backend, either it is number 458 of bytes, or it can be number of registers. */ 459 unsigned int va_list_gpr_size : 8; 460 461 /* Number of units of floating point registers that need saving in stdarg 462 function. */ 463 unsigned int va_list_fpr_size : 8; 464 };